Cigarette smoke contains various types of toxins&carcinogens. Among these, benzo[a]pyrene and other polycyclic aromatic hydrocarbons are regarded as important inducers of epithelial neoplasms. However, tobacco-specific N-nitrosoamines (TSNA), members of a unique class of systemic carcinogens, act as organ-specific carcinogens. One of these TSNA, the potent carcinogen 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK) induces adenocarcinoma in mice, rats and hamsters. The carcinogenic potential of N-nitrosoanatabine (NAT) and its contribution to the induction of lung tumors in laboratory animals and its metabolism is not known. The goal of the present collaboration is to synthesize [3H]-5-NAT for the purpose of metabolism and tissue distribution studies. By using a similar procedure as reported for NAT, we have prepared [3H]-5-NAT with high specific activity from starting material 5-bromo-3-pyridinecarboxaldehyde. A manuscript has been submitted to J. Labelled Compd. Radiopharm.